The Pete Incaviglia Rule

A player cannot be traded until one year after he signs with a major league team. The rule was instituted after the Expos traded Pete Incaviglia to the Rangers just months after drafting him. This MLB.com article says he was dealt because the Expos had trouble signing him. Incaviglia, who would go on to become an all-or-nothing hitter with the Rangers, was chosen eighth overall by the Expos in 1985.